Christina Wedén

Natural products in modern life science

With a realistic threat against biodiversity in rain forests and in the sea, a sustainable use of natural products is becoming more and more important. Basic research directed against different organisms in Nature could reveal unexpected insights into fundamental biological mechanisms but also new pharmaceutical or biotechnological possibilities of more immediate use. Many different strategies have been used prospecting the biodiversity of Earth in the search for novel structure–activity relationships, which has resulted in important discoveries in drug development. However, we believe that the development of multidisciplinary incentives will be necessary for a future successful exploration of Nature. With this aim, one way would be a modernization and renewal of a venerable proven interdisciplinary science, Pharmacognosy, which represents an integrated way of studying biological systems. This has been demonstrated based on an explanatory model where the different parts of the model are explained by our ongoing research. Anti-inflammatory natural products have been discovered based on ethnopharmacological observations, marine sponges in cold water have resulted in substances with ecological impact, combinatory strategy of ecology and chemistry has revealed new insights into the biodiversity of fungi, in depth studies of cyclic peptides (cyclotides) has created new possibilities for engineering of bioactive peptides, development of new strategies using phylogeny and chemography has resulted in new possibilities for navigating chemical and biological space, and using bioinformatic tools for understanding of lateral gene transfer could provide potential drug targets. A multidisciplinary subject like Pharmacognosy, one of several scientific disciplines bridging biology and chemistry with medicine, has a strategic position for studies of complex scientific questions based on observations in Nature. Furthermore, natural product research based on intriguing scientific questions in Nature can be of value to increase the attraction for young students in modern life science.

The population of the hypogeous fungus Tuber aestivum syn. T. uncinatum on the island of Gotland.

The aim of our study was to examine the genetic variation within Tuber aestivum on the Baltic island of Gotland, Sweden. Variation in such a limited geographical area should help illuminate the dispersal abilities of T. aestivum. Knowledge of the genetic variation in this northern outpost could also be useful in the selection of inoculum for the establishment of truffle orchards. Genetic structure and homogeneity of the population were studied using principal component and parsimony analyses of randomly amplified polymorphic DNA data. Our inventories showed that T. aestivum is abundantly distributed in suitable habitats on Gotland. The genetic variation observed suggests sexual reproduction and slow dispersal on the island. It is possible that the present population was established from one introduction, which may be due to ability to survive in this habitat rather than to rare colonising events. The T. aestivum population on Gotland may be an ecotype adapted to the climate and soil conditions on the island.

Tuber aestivum (syn. T. uncinatum ) biotopes and their history on Gotland, Sweden

This study aimed at testing the hypothesis that the genetically distinct Tuber aestivum population on the island of Gotland, Sweden, is adapted to habitats different from French T. aestivum populations. The soil structure, soil chemistry, bedrock, climate, vegetation and host tree continuity of 18 T. aestivum sites on Gotland were analysed and compared with data from France. We conclude that T. aestivum can grow in soils with a broad soil structure range and that no striking differences in soil chemistry were found. No T. aestivum indicator plants other than the host trees were found, but the host tree continuity on the T. aestivum sites on Gotland was more than 300 yr. If the T. aestivum population on Gotland constitutes an ecotype it is rather an adaptation to the colder and drier climate on Gotland. Selecting local T. aestivum inoculum for truffle orchards in northern Europe could be important for successful truffle production.

Truffle cultivation in Sweden: Results from Quercus robur and Corylus avellana field trials on the island of Gotland

Abstract The edible, ectomycorrhizal Burgundy truffle, Tuber aestivum Vitt., grows naturally on the islands of Gotland and Öland, Sweden. In 1999, 240 inoculated Quercus robur and Corylus avellana seedlings inoculated with French T. aestivum were planted in 10 experimental truffle orchards (truffières) on Gotland to investigate the possibility of truffle cultivation in Sweden. Truffle orchard management, mycorrhizal development and seedling growth were studied. Fourteen additional truffle orchards containing more than 2000 Q. robur were established during 2000 and 2001. In 2004, T. aestivum mycorrhizae were detected in all truffle orchards. In 2005, the first T. aestivum truffle was found, 6 years after planting. This is the first cultivated truffle in Scandinavia and despite the northerly location they were produced within a timescale comparable with France. Tuber aestivum mycorrhizae survived in soils which differed from naturally producing locations by having a sand content > 95%, pH ≤6.4 and calcium content ≤0.1%. In a second series of experiments Swedish Q. robur, C. avellana and Carpinus betulus seedlings were inoculated with Swedish T. aestivum. Eleven months after inoculation T. aestivum mycorrhizae were found in 0–78% of the seedlings, depending on species, inoculation treatment and substrate. Because of the continuing decline of oaks in Sweden and associated fauna and flora, truffle cultivation may favour oak forest restoration programmes as well as making a direct contribution to rural economies.